<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="https://cdn.jsdelivr.net/npm/vue@2.6.10/dist/vue.js"></script>
</head>

<body>
    <div id="app">
        <button @click="fullName='zeng ziyi'">奇迹</button>
        <h2>数据是{{fullName}}</h2>
    </div>
    <script>
        Vue.config.productionTip = false;
        
        const vm = new Vue({
            el: "#app",
            data() {
                return {
                    firstName:"wang",
                    lastName:"zhongwang"
                }
            },
             //配置项，专门在里面书写计算属性
             computed:{
                    // 只读
                    // fullName(){},

                    fullName:{
                        get(){
                            console.log("getter");
                            return(
                                this.firstName.toLowerCase()+" "+this.lastName.toLowerCase()
                            );
                        },
                        set(val){
                            // set函数中的参数就是计算属性被设置的值
                            console.log("setter",val);
                            // setter中的逻辑我们可以自由发挥
                            this.firstName=val.split(" ")[0];
                            this.lastName = val.split(" ")[1];
                        }
                    }
                }
        })
</script>
</body>

</html>